The invention relates generally to a deicing composition and method of using the same and more particularly, to a deicing composition comprising succinate salts and methods of using succinate salt compositions for deicing applications at airport facilities and other applications involving specialty materials as well as for highway, residential and commercial deicing.
Chemical deicing is routinely used during the winter season to maintain safer mobility on United States highways and airports. There are numerous materials and compositions presently used for such deicing applications. However, there are many disadvantages to the presently used materials, including their corrosiveness, cost and their impact on the environment.
Common road salt is the most widely used deicing chemical on highways, driveways, sidewalks, etc. It is generally effective, inexpensive, reliable and easy to store and apply. As described in "Highway Deicing: Comparing Salt and Calcium Magnesium Acetate", Special Report 235, Transportation Research Board Committee on the Comparative Costs of Rock Salt and CMA for Highway Deicing, Washington, D.C., (1991), incorporated herein by reference, an estimated 10 million tons of road salt, at $35/ton, is used each year.
One of the major problems with road salt is that due to its corrosiveness. It has the potential to cause costly damage to highway infrastructure, driveway and sidewalk surfaces, motor vehicles and the environment. Structural damage may include concrete degradation and steel corrosion, which generally leads to high maintenance expenditure. Foliage burns, soil compaction and water contamination are some of the adverse environmental manifestations of sodium chloride use.
As described in, W. L. Miller, "Ways to Help Bridges and Deicers Coexist: CMA Cuts Corrosion on Zilwaukee Bridge", Better Roads, (February, 1993), and R. Strawn, "CMA has Role to Play in Critical Applications", T. Kuennen, Ed., Roads & Bridges, (March, 1993), each of which is hereby incorporated by reference, due to the problems associated with the corrosiveness of generally used salts as road deicing chemicals, a less harmful road deicing chemical, namely calcium magnesium acetate (CMA) was commercialized. Calcium magnesium acetate is known to inhibit concrete degradation and corrosion. It is also known to be less harmful to the environmental than conventional road salt. However, one of the downsides of CMA is its cost, which at $925/ton, is 20 times as much as common road salt. Further, CMA is a less than fully satisfactory deicer.
ICE BAN.RTM. is a recently developed deicer composition available from Ice Ban America, Inc. As described at the company's web site, http://www.iceban.com, ICE BAN.RTM. is a natural liquid concentrate residue from the wet milling of corn and the production of alcohol. It is generally non-corrosive and has good anti-icing and deicing properties. However, this product has not proved to be fully satisfactory. One downside of ICE BAN.RTM. is that it is formulated as a liquid deicer. Equipment currently used for spreading of conventional deicers are configured for solid deicers. Switching to a liquid deicer would require expensive equipment reconfigurations, leading to significant capital investment in addition to the capital required for liquid storage tanks. The viscosity of the liquid at low temperatures can pose additional problems.
Another currently available deicer is known as CF7, which is based on potassium acetate, manufactured by CRYOTECH, and which is believed to be scheduled for testing at airport applications. Airport and airbase deicers need to comply with stringent criteria and standards. It is believed that CF7 may pose corrosion problems in connection with certain airport applications and thus may not comply with standards for deicing aircraft metals.
EP Publication No. 0 077 767 discloses, inter alia, discloses a dicarboxylic acid mixture (hereinafter "DAM") consisting of adipic acid (30-35% wt), glutaric acid (40-50% wt) and succinic acid (20-25% wt) in the form of a potash salt which is asserted to be suitable for airport deicing. This formulation is in liquid form and is believed to possess deicing characteristics. However, it is believed that it does not comply with the corrosion standard for aircraft metals, and, in particular, does not comply with the corrosion standards for dichromate treated magnesium, which is the aircraft metal alloy that is most susceptible to corrosion.
The reference also discloses a combination of potassium salt of pure succinic acid, urea and water as an anti-freeze solvent (35.5 parts by weight:25 part:41.5 parts). The reference also states that the use of pure potassium succinate was less favorable as an antifreeze and corrosion inhibitor than the dicarboxylic acid mixtures disclosed therein, clearly discouraging use of potassium succinate in favor of a mix of certain carboxylic acids. Sixteen years have passed since this application was published and no commercial product based on the disclosure therein has gained any measure of market acceptance.
Thus, it is desirable to provide an improved deicing composition and method of using the same which is more commercially viable than those which have been suggested in the past.